1. Field of the Invention
The present invention relates to a developer supplying cartridge that is detachably mountable to a main body of an electrophotographic image forming apparatus, and an electrophotographic image forming apparatus using the same.
Here, an electrophotographic image forming apparatus (hereinafter, referred to as “image forming apparatus”) is the one that forms an image on a recording medium employing an electrophotographic image forming process. Examples thereof include an electrophotographic copying machine, an electrophotographic printer (such as an LED printer and a laser beam printer), an electrophotographic facsimile apparatus and an electrophotographic word processor.
Here, a recording medium is an article on which an image is formed, for example, a recording sheet or an OHP sheet.
2. Description of the Related Art
Conventionally, in an image forming apparatus employing an electrophotographic image forming process, employed is a process cartridge system in which an electrophotographic photosensitive member and process means acting on the electrophotographic photosensitive member are integrated into a cartridge, which is detachably mountable to a main body of the image forming apparatus. By this process cartridge system, since a user himself/herself can conduct the maintenance of an apparatus without labors of a service person, operability can be improved.
Furthermore, an electrophotographic photosensitive member and process means acting on the electrophotographic photosensitive member have respective different product lives. Therefore, there is the one in which a process cartridge integrally incorporating the electrophotographic photosensitive member and a developing device, and a developer supplying cartridge supplying a developer to the process cartridge are formed to be separate parts.
Here, in the case where the process cartridge and the developer supplying cartridge are constructed to be separate parts, in the state in which both the developer supplying cartridge and the process cartridge are mounted in an image forming apparatus, the developer is supplied from the developer supplying cartridge to the process cartridge. Furthermore, employed is the system in which a developer is supplied in small quantities from a supplying opening that is provided in the developer supplying cartridge to a supplied opening that is provided in the process cartridge.
Moreover, on the occasion when a user replaces the process cartridge and the developer supplying cartridge, the leakage of a developer needs to be prevented. Therefore, a supplying opening and a supplied opening, in order to prevent the leakage of the developer therearound, are thought to be provided with a shutter that can be opened and closed.
As a general supplying opening shutter construction, there are a slide system in which a plate shutter member is slid to open and close a supplying opening, and a disk rotary system in which a disk-like shutter member provided with a hole is rotated to open and close a supplying opening. Furthermore, there is a rotary valve system in which a cylindrical member formed with a through-hole in an outer circumferential surface thereof is rotated, whereby a supplying opening is opened and closed (Japanese Patent Application Laid-Open No. H07-036269).
Incidentally, in the slide system or the disk rotary system, a layout space of a shutter is required other than the extent of the supplying opening for opening and closing the supplying opening. Whereas, the rotary valve system is advantageous for downsizing of an apparatus, since the supplying opening can be opened and closed within the extent of the cylindrical member.
In the above-mentioned rotary valve system, for example, a housing member is provided in the position of a supplying opening for discharging the developer. Thus, it is conceivable that a cylindrical member having a through-hole is rotatably mounted in this housing member, and this cylindrical member is rotated to open or close the supplying opening. In this example, the cylindrical member is rotated to cause the through-hole to communicate with the supplying opening, thereby enabling to supply the developer. In addition, the supplying opening is closed with the cylindrical member by shifting the positions of the through-hole and the supplying opening, thereby enabling to stop to supply the developer.
In such construction, a particular space for the rotation of the cylindrical member is unnecessary, and downsizing of a cartridge can be achieved.